The goal of this study is to gain an understanding of genomic copy number variants in humans and other primates. Copy number variants are large stretches of DNA sequence repeated a different number of times among the genomes of normal humans, which can influence transcriptional and translational levels (the amount of mRNA and protein created for a particular gene) and therefore susceptibility to diseases such as HIV infection. We will characterize the relationship between copy number variants and gene expression variation within and between humans and other primates, which will allow us to identify copy number variants that may be of considerable functional and biomedical significance. Narrative: The goal of this study is to gain an understanding of the structure and evolution of genomic copy number variation in primates and its impact on gene expression. Specifically, we will (i) assess whether levels and patterns of copy number variation in non-human primates are similar to those for humans and test for heterogeneity in the inter-specific fixation rate for copy number gains and losses, and (ii) characterize the relationship between copy number variants (CNVs) and gene expression variation across different timescales of primate evolution. Our work will provide the most comprehensive understanding to date of the relationship between copy number and gene expression variation in primates, allowing us to identify specific CNVs that may be of considerable evolutionary and biomedical significance. Our research team, which includes leaders in both the primate copy number variation and gene expression fields, is well positioned to collaboratively address these important issues.